Lagging and freezing are generally signs that your phone's random access memory (RAM) is full or almost full. RAM is tied up by the programs your phone is currently running. To free up your RAM, you must close some of these programs. Go to "Task Manager" and close remnant programs you aren't using so the device isn't overloaded with running programs.

Check the ends of your charger to ensure they are undamaged and free of dust and debris. If there is any visible damage, you may need a new charger. If there is any dust or debris, clean it using compressed air or a cotton swab and isopropyl alcohol.

If there is no visible damage, but your phone charges by another method, that may mean your charger is defective or has internal damage and should be replaced. Try a different method of charging, like your car charger. If you have access to a second wall charger, try that one. Try plugging your phone into a computer using its USB cable and see if it responds or begins charging.

Make sure the metal contacts on the battery and phone are touching. If you are unsure, gently push the battery to confirm the metal contacts are touching and try charging the phone.

If your phone begins charging, then the battery and phone are not making proper contact and small piece of paper or cotton can be stuck between the other edge of the battery and the phone case to create a tighter fit.

More likely than not, you are unable to connect to the internet due to your Wi-Fi Settings. To fix this, alter your settings by following this procedure: Menu > Settings > Wireless Manager. Then select "Wi-Fi" to enable the wireless receiver. If there are any Wi-Fi signals in your area, you should see them on your Wi-Fi menu now. Select the wireless network you wish to connect to, enter the password if needed, and select "Connect."

Your phone's RAM is full so it stops displaying incoming callers. Similar to the cold boot described above, press and hold the end/power button until your phone powers down. Keep it powered down for at least sixty seconds, then reboot your phone.

A cold boot will fix the most basic software issues. Press and hold the end/power button until your phone powers down and the screen turns off. Keep it powered down for at least sixty seconds so the RAM can reset. After sixty seconds, reboot your phone. If the problem persists, move on to a battery reset.

First, press and hold the end/power button to power down your phone. Then remove the battery and SD card by referring to the battery installation guide. Wait three minutes to allow the RAM to reset. After three minutes, reinstall the battery and power your phone on. If this fixes the problem, then reinstall the SD card.

When all else fails, a factory or hard reset should fix any software issues with your phone. WARNING, a hard reset restores your phone to its factory settings and erases all your personal information, programs installed, and customized settings. Back up everything you can onto your SD card or computer.

After backing up your information, remove the SD card and charge your battery. Then follow this procedure: Start > Settings > Advanced > Setup > Restore Factory Default. Then select "Yes." Your phone will reboot itself two to three times before the process finishes.

If all else fails, call AT&T wireless support to help resolve issue. You may need to provide your phone number and IMEI number*.

Similar to the battery reset described above, reference the battery installation guide and remove the battery for at least ten minutes. Then reinstall it and try to power on the device by pressing and holding the end/power button.

The firmware or read-only memory (ROM) contains the critical files your phone needs to function properly. If it has been corrupted in some way, reinstall/update it by following the directions on AT&T's page.

First, press and hold the end/power button to power down your phone. Then remove the battery by referring to the battery installation guide and wait a few seconds. Then reinstall the battery and turn the phone on.

Try updating the read-only memory (ROM) by following the directions on AT&T's site. WARNING, ROM updates delete all your personal settings and data, so back up everything you can onto your SD card or computer.